Creatine is an amino acid synthesized in the body and obtained through dietary sources. It plays a key role in cellular energy production. In research, creatine has been shown to support athletic performance and muscular health. Recent studies indicate it may also support the body’s response to strenuous exercise.
Creatine becomes phosphocreatine inside the body. When the bond between creatine and phosphate is hydrolyzed, it provides the energy to form a new bond between adenosine diphosphate (ADP) and phosphate, thus playing a critical role in adenosine triphosphate (ATP) metabolism. In conditions of increased energy demand or those involving a reduced supply of blood or oxygen, phosphocreatine restores ATP concentration to satisfy the energy needs of the cell.
Anaerobic glycolysis is the main source of energy for sprinting, typically lasting from 6 seconds to 30 seconds. In the case of repeated sprinting, phosphocreatine becomes involved in ATP resynthesis. Decreased phosphocreatine levels have been associated with an inability to maintain power during strenuous exercise.
A randomized controlled trial by Bogdanis and colleagues explored the efficacy of supplementation with oral creatine on power output during strenuous exercise. Sixteen healthy, college-aged participants were included in the study. The baseline assessment involved a physical evaluation consisting of repeated sprinting tests. The treatment consisted of 75 mg of creatine per kilogram of body mass four times daily for 5 days. The repeated sprinting tests were then administered as a post-test. Certain biometrics were collected at baseline and post-test, including VO2max, a measure of the volume of oxygen consumed during exercise.
Post-study analysis showed improvements in mean speed, mean power, and fatigue index. Sprint running performance changes were observed, even in the presence of an increase in body mass. The authors suggest that the improvements in exercise performance were likely due to phosphocreatine metabolism because of statistical trends in VO2 output.
Study limitations included a small sample size and homogeneity in age, gender, and health status. The authors cite a lack of certain biometrics, such as muscle biopsy, as a limitation to the study design.
Although the main sources of dietary creatine are lean meat and fish, a systematic review explored the benefits of creatine supplementation among vegetarian and omnivorous athletes. The results showed an increase in lean tissue mass, type II fiber area, muscular strength, muscular endurance, and an increase in memory in those with a vegetarian diet.
Due to its role in cellular energy production, creatine may support many other functions in human health. Some research suggests creatine may support brain health in cases with decreased energy availability and sleep deprivation. Creatine may also support the prevention of age-related muscle atrophy and sarcopenia in the elderly. Supplementation with creatine has been shown to increase muscular creatine content and augment certain aspects of training in the elderly, which may be relatively safe in this population.
Creatine is an amino acid that may support athletic performance, the building of lean muscle mass, and cellular energy function. It may also support exercise endurance and certain aspects of brain health and age-related changes.
By Colleen Ambrose, ND, MAT